Motor engine worked by combustible gas



(NoModeL) 2 Sheets-Sheetill. N. A. OTTO.

MOTOR ENGINE WORKED BY GOMBUSTIBLE'GAS. No. 383,066. Patented May 15, 1888.

d' a en-ed at) N PETERS, Photxruihographer, .Wushmghm, D. c.

' 2 Sheets-heet 2.

(No Model.)

N.A..OTTO. MOTOR ENGINE WORKED BY GOMBUSTIBLE GAS.

No. 383,065.' Patented May 15, 1888.

w M i/V' T n i rrED STATES PATENT Orrin.

I NICOLAUS AUGUST OTTO, OF COLOGNE, PRUSSIA, ASSIGNOR TO THE GAS MOTOREN FABRIK DEUTZ, OF DEUTZ ON THE RHINE, GERMANY.

MOTOR ENGINEZ WORKED BY COMBUSTlBLE GAS.

SPECIFICATION forming part of Letters Patent No. 383.065, dated May 15, 1888.

Application filed September 26, 1887. Serial No. 250,734,

(No model.) Patented in England August 23, 1887, No. 11,503; in

Belgium September 3, 1887, No. 78,765, and in Italy November 10, 1887, XLIV, 176.

To all whom it may concern.-

Be it known that I, NIOOLAUS AUGUST OTTO, a citizen of Prussia, residing at Cologne, in the German Empire, have invented new and useful Improvements in Motor-Engines \Vorked by Combustible Gas, Vapor, or Spray, and Air, (for which I have obtained patents in Belgium, dated September 3, 1887, No. 78,765; Italy, November 10, 18S7,Vol. XLIV, No. 176, and have made application for patent in Great Britain, which patent when granted will bear date August 23, 1887, No. 11,503,) of which the following is a specification.

This invention relates to that description of gasmotor engines in which the firing of a combustible charge takes place once in every four strokes of the piston, such as that known as the Otto engine.

The present improvements have for their object to produce a greater development of power by the formation in the cylinder of an explosive mixture rich in gas and free from products of combustion, and also to produce an increased useful effect and saving in gas consumption by the expansion of the products ing strokes a high degree of expansion, and

. consequently an increased useful effect, is obtained.

The power of the engine may be varied according as a greater or less quantity of combustible gas or gaseous mixture is admitted to .the air in the cylinder, and according as the charge is admitted during a greater or less -part of the suctionstroke so, as to vary the degree of expansion.

In constructing the gasinotor engine for op-. erating in the abovedescribed manner the front end of the enginecylinder is closed and is provided with a suction and delivery valve communicating, respectively, with the atmosphere and with a closed reservoir, so that at each forward stroke of the piston a charge of air is forced thereby at a certain pressureinto thereservoir. Apipeleads:fromthis reservoir to the back end of the cylinder, where it is provided with a valve, and where it communicates with the inlet-passage of the cylinder, also governed by a valve, both these valves being actuated by cams on a way-shaft revolving at half the speed of the engine-shaft. These valves are opened when the piston arrives near the end of its expelling instroke, so that the compressed air can then pass from the reservoir into the cylinder, expelling the remainder of the products of combustion through the open escape-valve as the piston completes its instroke,at the end of which the air in the reservoir will have sunk to about atmospheric pressure. The escapevalve being now closed, the piston commences its suction-stroke, and the valve of a gaspipe leading into the inletpassage being more or less opened, gas, together with a greater or less proportion of air admitted by the air-reservoir valve,is drawn into the charge of air contained in the cylinder. 'When the piston has performed acertain part of its outstroke, the gas and air valves are closed, so that as the piston completes its stroke the combustible charge in the cylinder is expanded below atmospheric pressure. At the commencement of the following instroke the combustible charge will first again attain atmospheric pressure, and will then be com pressed to a greater or less degree on the completion of such stroke.

The accompanying drawings show the construction of a gas-motor engine operating according to my above-described invention.

Figure l is a longitudinal section of the en gine. Fig. 2 is a sectional plan. Figs. 3, at, and 5 show crosssections. Fig. 6 is a part side view; and Fig. 7 is a diagram of the action.

The space B in the working' cylinder in front of the piston A is inclosed bya cover, as shown,

and serves as air-compressor, the air being drawn in on the instroke of the piston, and, after compression to a certain extent, forced into a reservoir, D, through pipe 6 and inlet and delivery valvesff, Fig. 5.

The valves and slide of the engine are worked by means of the way-shaft g, which makes one revolution for every two of the crank-shaft. The diagram of the pistons motion transferred to the crank-path of the wayshaft is shown at Fig. 7. From 1 to 2 combustion and developmentof power take place in the cylinder. From 2 to 3 the products of combustion are expelled. From 3 to 4 the charge of combustible mixture is drawn in, and from 4 to 1 it is compressed. On the expelling-stroke, before the piston has performed the whole of its stroke and is situated at a point corresponding with,say, the point ct, Fig. 7, a cam on the way-shaft g, Fig. 3, opens the air-valve g by means of a lever, h, and the inlet-valve nby means of thelever p, whereupon the compressed air contained in the reservoir D passes through pipe e and passages Z Z and valve n, into the space. 0 of the cylinder behind the piston, where it drives out the resid ual products of combustion through the discharge-valve 1". When the piston has arrived at the end of its instroke, the pressure in the reservoir D will have sunk to that of the atmosphere, and the discharge-valve r is closed while the gas-inlet valve 2' is opened. The piston then by itsiputstroke draws gas in through pipe 8 am'olg the air contained in the compression-space O, and with it any desired quantity of air, according as the air-valve 9 may be more or less opened or closed sooner or later. A variable degree of filling is obtained by cutting off the gas and air supply by closing the valves 9, t, and n at any desired point of the stroke of the piston-such as, for instance, the point b-during the stroke from 3 to 4, Fig. 7. By the continued motion of the piston the charge in the cylinder is now expanded to a certain degree below atmospheric pressure, so that at the return stroke the charge is first brought back to atmospheric pressure and is then compressedin the compression-space. By this arrangement is attained, first, that the charge is freed as much as possible from combustion products,and consists of a comparatively rich gas-mixture containing the necessary quantity of oxygen for effecting perfect combustion, while, secondly, by cutting off the gas and air supply at any desired point of the suction-stroke any desired degree of expansion of the combustion-gases may be obtained during the working-stroke. The motor-engine can therefore be worked with any desired quantity of combustible mixture from the smallest possible charge up to the complete filling of the cylinder, according as the inlet-valve a, the air-valve g, and the gas-valve t are closed sooner or later.

AS shown on the drawings, each engine may be worked with a definitely-fixed degree of expansion, the fixed cams on the way-shaft that actuate the valves 9 andn being so formed as to effect the closing of the valves at a definite point of the stroke corresponding to the curve 3 to 4, Fig. 7. \Vith this arrangement the gas-inlet valvei is worked by a sliding cam with incline controlled by the governor, which either admits a larger or smaller quantity of gas or cuts off the supply entirely during one or more working-strokes, whereby the speed of the engine is regulated.

Instead of an inclined cam a straight cam may be used, the regulation being effected by causing the governor to move the cam to one side, so as not to open the gas-valve when the maximum speed is exceeded. The regulation of the engine may, however, also be effected by varying both the degree of expansion and the supply of gas, the time of closing the valves 9, n, andi being varied simultaneously, for which purpose the cams that open the same are formed with steps or with an incline, and are shifted by the governor. In the arrangement shown at Fig. 3 the requisite air for forming the explosive charge is drawn in through the reservoir B; but it. can also be drawn directly from the atmosphere through a branch pipe, 25, Fig. 4, the air valve 9 being in that case closed during the suctionstroke. The valve 0 opens automatically during the suction-stroke, so as to admit the required proportion of air and gas pass into the cylinder through the inlet-valve. The expansion of the cylinder-charge is in this case regulated by closing the gas-valve iand inlet-valve n at the corresponding point of the pistons stroke.

This degree of expansion may be a fixed one by working the valves 9 and n by means of fixed cams of a determined length. The regulation of the engine is in this case effected by causing the governor to act upon the gas-inlet valve 73 in the before-described manner; but it may also be effected, as before described, by varying both the degree of expansion and the time of closing the gas-valve. The ignition of the charge can be effected in any known manner.

Instead of combustible gas, combustible vaponsr spray may be employed, and the engine may be either vertical, horizontal, or inclined, and may have either one or several cylinders.

Having thus described the nature of my invention and. the best means I know for carrying the same into practical effect, I claim- In gas-motor engines working with a compression-space and with a cycle of four strokes, the method of replacing the residual products of combustion remaining in the cylinder at the end of the expelling-stroke by a combustible charge by first driving out the said products by means of a charge of atmospheric air and then drawing in a variable quantity of combustible gas with or without lol admixture of air to mix with the said charge to this specification, in the presenoe of two subof air, the combined charge being partially scribing witnesses, this 3d day of September, expanded below atmospheric pressure during A. D. 1887.

r the suction-stroke and compressed during the NICOLAUS AUGUST OTTO.

5 return stroke, substantially as herein de- Witnesses:

scribed. GUSTAVE ALBERT OELRICHS, I In testimony whereof I have signed my name MICHEL MtiLLER, 

